Slow depolarizing electrical stimuli reveal differential time courses of nociceptor recovery after prolonged topical capsaicin in human skin.

ABSTRACT:

Background

We examined de-functionalization and temporal functional recovery of C-nociceptor evoked pain after topical 8% capsaicin applied for 4 consecutive days.

Methods

Capsaicin and placebo patches were applied to human forearm skin (n = 14). Cold, warmth and heat pain thresholds, pain NRS to electrical and thermal (48°C, 5 s) stimuli and axon reflex flare were recorded weekly for 49 days. Mechanical and heat sensitive ('polymodal') nociceptors were activated by single electrical half-period sinusoidal pulses (0.5 s, 1 Hz). Mechanical and heat insensitive ('silent') nociceptors were activated by 4 Hz sinusoidal stimuli.

Results

Capsaicin abolished heat pain. Sensation to electrical sinusoidal stimulation was reduced but never abolished during the treatment. Pain t

SUBMITTER: Tumbala Gutti D 

PROVIDER: S-EPMC11671321 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature